String html="<html><body><img src='{IMAGE_URL}' /></body></html>";
Bitmap bitmap = YOUR_BITMAP;
// Convert bitmap to Base64 encoded image for web
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream.toByteArray();
String imgageBase64 = Base64.encodeToString(byteArray, Base64.DEFAULT);
String image = "data:image/png;base64," + imgageBase64;
// Use image for the img src parameter in your html and load to webview
html = html.replace("{IMAGE_URL}", image);
webview.loadDataWithBaseURL("file:///android_asset/", html, "text/html", "utf-8", "")